October 8, 2012

Rasmussen Throws Cold Water on Romney’s Post-Debate Bounce

While it’s still too early to judge the size of Romney’s post-debate bounce, some of the worst news for Mitt is coming from an unlikely source: the traditionally-GOP leaning Rasmussen Reports.

Although Rasmussen initially lurched in Romney’s direction, Rasmussen’s national tracking poll now shows a tied race. Similarly, their state polls in Iowa and Colorado show Obama actually making gains since their pre-debate polls, giving Romney an average post-debate gain of just .2 points within Rasmussen polls—and moving the pollster-wide average of a post-debate shift to a slim Romney+2.8.

And the evidence of even .2 points worth of movement is relatively weak. Obama’s post-DNC lead averaged just .7 points in Rasmussen’s national tracker, suggesting few, if any gains. the movement in Rasmussen’s state polls looks more like regression to the mean than evidence of genuine movement. Notice that Romney made gains in Florida and Virginia, two states where Rasmussen’s prior polling leaned less toward Romney than the average, but Romney lost ground in Colorado and Iowa, two states where Romney’s prior polling was a little too good to be true.

Additionally, the Iowa and Colorado polls were conducted entirely on Sunday, and Rasmussen’s decent results for the president were consistent with a strong polling day in the national tracker, as well as in PPP’s poll of Virginia.

One reason why Rasmussen might not show much of a shift in Romney’s direction: if other pollsters’ movement was attributable to a shift in party-ID, then Rasmussen wouldn’t show any shift since they hold party-ID constant. If that’s ultimately the explanation, it might be wise to defer to the other polls.

Ultimately, Rasmussen is just one pollster; the broader set of polls makes it clear that Romney has made gains since the debate. But Rasmussen has conducted more post-debate polling than any other source, so it’s worth noting that their data is driving the numbers back in Obama’s direction. Whether the broader universe of pollsters will eventually side with Rasmussen or not remains to be seen.